1. Field of the Invention
The present invention relates to a sealing device in accordance with a sealing technique. The sealing device in accordance with the present invention is used, for example, as a hub bearing seal in an automotive associated field, or is used in each of associated fields of an electrical appliance, an industrial machine, a bicycle and the like.
2. Description of the Conventional Art
Conventionally, there has been known a sealing device 51 shown in FIG. 6, and the sealing device 51 is used as a hub bearing seal in a bearing portion of a wheel suspension apparatus for a motor vehicle, and is constructed by a combination of a mounting ring 52 which is fitted to a bearing outer ring 61 and is made of a rigid material such as a metal or the like, and a rubber-like elastic body 53 which is attached to the mounting ring 52, and a side lip 54 which slidably comes into close contact with an end surface in an axial direction (including a curved surface portion having a circular arc cross sectional shape and being formed in an inner peripheral portion of the end surface in the axial direction. The same is applied hereinafter too.) 62a of a hub 62 corresponding to a bearing inner ring is formed by the rubber-like elastic body 53 (refer to Japanese Unexamined Patent Publication No. 9-287619 and Japanese Unexamined Patent Publication No. 2005-351392).
The sealing device 51 is used as the hub bearing seal as mentioned above, and seals it in such a manner as to prevent foreign materials such as muddy water, dust and the like in an outer portion of the bearing from making an intrusion into an inner portion of the bearing, however, there occurs a case that the side lip 54 in one sealing device 51 is interfered with the mounting ring 52 in an upper sealing device 51 at a time of coaxially piling up a plurality of sealing devices 51 at a time of product shipping or the like, whereby there is a disadvantage that an adhesion phenomenon is caused, a lubricating grease previously applied to the side lip 54 is scraped off, or the like. In this case, in order to prevent the slide lips 54 from being interfered with each other at a time of piling, it is preferable to set a length in an axial direction of an outer peripheral tubular portion 52a in the mounting ring 52 large, however, since an attaching space s in the bearing outer ring 61 is actually limited, it is impossible to set the length in the axial direction so large as to prevent the interference.